Item 3.01 Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing. On October 2, 2026, CECO Environmental Corp. (the “ Company”), acting pursuant to authorization from its Board of Directors (the “ Board”), notified the Nasdaq Global Select Market (“ Nasdaq”) of its intention to voluntarily withdraw the primary listing of its common stock, par value $0.01 per share (the “ Common Stock”), from Nasdaq and transfer the primary listing to the Texas Stock Exchange LLC (“ TXSE”). The Company expects that trading of the Common Stock on Nasdaq as a primary listing will end at market close on October 16, 2026, and that trading on TXSE as a primary listing will begin at market open on October 19, 2026. The Common Stock has been approved for listing on TXSE, where it will continue to trade under the stock symbol “ CECO.”

Item 7.01 Regulation FD. The Company issued the news release attached hereto as Exhibit 99.1 in connection with the transfer of the primary listing of the Common Stock to TXSE. The information contained in Item 7.01 of this Current Report on Form 8-K (the “ Report”) and in Exhibit 99.1 to the Report shall not be deemed “filed” with the Securities and Exchange Commission for purposes of Section 18 of the Exchange Act of 1934, as amended (the “ Exchange Act”), or otherwise subject to the liability of that section, and is not incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act.